Intergranular pinning properties in high-T-c superconductor by ac susceptibility response

From the ac susceptibility measurements, both the intergranular and intragranular peaks in the X'' imaginary part for the granular YBa2(Cu0. 9Cd0.1)(3)O7- delta superconductor can be observed clearly. Our finding of the exponent n similar to 1 in the scaling law of temperature dependence of critical current density indicates that the grain boundary junction in YBa2(CU0.9Cd0.1)(3)O7-delta Should be SIS-type. The effective pinning potential is found to be inversely proportional to the power of magnetic field. The current density dependence of the U(T,H,J) is found to obey the inverse power law of the collective pinning theory. This indicates that the intergrain Josephson tunneling, which forms as a weak link network, exhibits a collective pinning behaviour.